CCI-779 concentrate formulations

ABSTRACT

This invention provides CCI-779 cosolvent concentrates which are useful in preparing a parenteral formulation of rapamycin 42-ester with 3-hydroxy-2-(hydroxymethyl)-2-methylpropionic acid (CCI-779) following admixture with a diluent.

BACKGROUND OF THE INVENTION

This invention relates to parenteral formulations of rapamycin 42-esterwith 3-hydroxy-2-(hydroxymethyl)-2-methylpropionic acid (CCI-779).

Rapamycin is a macrocyclic triene antibiotic produced by Streptomyceshygroscopicus, which was found to have antifungal activity, particularlyagainst Candida albcans, both in vitro and in vivo (C. Vein et al., J.Antibiot. 28, 721 (1975); S. N. Sega et al., J. Antibiot. 28, 727(1975); H. A. Baker et al., J. Antibiot. 31, 539 (1978); U.S. Pat. No.3,929,992; and U.S. Pat. No. 3,993,749). Additionally, rapamycin alone(U.S. Pat. No. 4,885,171) or in combination with picibanil (U.S. Pat.No. 4,401,653) has been shown to have antitumor activity.

The immunosuppressive effects of rapamycin have been disclosed.Cyclosporin A and FK-506, other macrocyclic molecules, also have beenshown to be effective as immunosuppressive agents, therefore useful inpreventing transplant rejection (R. Y. Calne et al., Lancet 1183 (1978);and U.S. Pat. No. 5,100,899). R. Martel et al. (Can. J. Physiol.Pharmacol. 55, 48 (1977)) disclosed that rapamycin is effective in theexperimental allergic encephalomyelitis model, a model for multiplesclerosis; in the adjuvant arthritis model, a model for rheumatoidarthritis; and effectively inhibited the formation of IgE-likeantibodies.

Rapamycin is also useful in preventing or treating systemic lupuserythematosus (U.S. Pat. No. 5,078,999), pulmonary inflammation (U.S.Pat. No. 5,080,899), insulin dependent diabetes mellitus (U.S. Pat. No.5,321,009), skin disorders, such as psoriasis (U.S. Pat. No. 5,286,730),bowel disorders (U.S. Pat. No. 5,286,731), smooth muscle cellproliferation and intimal thickening following vascular injury (U.S.Pat. Nos. 5,288,711 and 5,516,781), adult T-cell leukemia/lymphoma(European Patent Application 525,960 A1), ocular inflammation (U.S. Pat.No. 5,387,589), malignant carcinomas (U.S. Pat. No. 5,206,018), cardiacinflammatory disease (U.S. Pat. No. 5,496,832), and anemia (U.S. Pat.No. 5,561,138).

Rapamycin 42-ester with 3-hydroxy-2-(hydroxymethyl)-2-methylpropionicacid (CCI-779) is ester of rapamycin which has demonstrated significantinhibitory effects on tumor growth in both in vitro and in vivo models.The preparation and use of hydroxyesters of rapamycin, includingCCI-779, are disclosed in U.S. Pat. No. 5,362,718.

CCI-779 exhibits cytostatic, as opposed to cytotoxic properties, and maydelay the time to progression of tumors or time to tumor recurrence.CCI-779 is considered to have a mechanism of action that is similar tothat of sirolimus. CCI-779 binds to and forms a complex with thecytoplasmic protein FKBP, which inhibits an enzyme, mTOR (mammaliantarget of rapamycin, also known as FKBP12-rapamycin associated protein[FRAP]). Inhibition of mTOR's kinase activity inhibits a variety ofsignal transduction pathways, including cytokine-stimulated cellproliferation, translation of mRNAs for several key proteins thatregulate the G1 phase of the cell cycle, and IL-2-induced transcription,leading to inhibition of progression of the cell cycle from G1 to S. Themechanism of action of CCI-779 that results in the G1 to S phase blockis novel for an anticancer drug.

In vitro, CCI-779 has been shown to inhibit the growth of a number ofhistologically diverse tumor cells. Central nervous system (CNS) cancer,leukemia (T-cell), breast cancer, prostate cancer, and melanoma lineswere among the most sensitive to CCI-779. The compound arrested cells inthe G1 phase of the cell cycle.

In vivo studies in nude mice have demonstrated that CCI-779 has activityagainst human tumor xenografts of diverse histological types. Gliomaswere particularly sensitive to CCI-779 and the compound was active in anorthotopic glioma model in nude mice. Growth factor(platelet-derived)-induced stimulation of a human glioblastoma cell linein vitro was markedly suppressed by CCI-779. The growth of several humanpancreatic tumors in nude mice as well as one of two breast cancer linesstudied in vivo also was inhibited by CCI-779.

A primary obstacle towards the formulation of CCI-779 as a parenteraldosage form is the poor aqueous solubility, which is less than 1 μg/ml.The drug is a non-electrolyte and approaches such as pH adjustment andsalt formation are not useful for improving the aqueous solubility.CCI-779 has poor solubility in pharmaceutically acceptable vegetableoils but CCI-779 is soluble in certain water-miscible organic solventsthat are acceptable for parenteral administration. These includeethanol, propylene glycol, polyethylene glycol and dimethylacetamide.Two problems or limitations exist with respect to the formulation ofCCI-779 in these organic solvents. First, chemical instability has beennoted in virtually all solvents. The instability can be due to oxidativedegradation of CCI-779 or to cleavage of a lactone bond, resulting inthe formation of the ring opened seco-CCI-779. Second, formulations ofCCI-779 in organic solvents will precipitate upon dilution with aqueousinfusion solutions, such as 0.9% Sodium Chloride Injection or 5%Dextrose Injections, or with blood. This is a primary limitation to theuse of water miscible organic solvents, also referred to as cosolvents,when used as vehicles for highly water-insoluble compounds.

SUMMARY OF THE INVENTION

This invention avoids the aforementioned problems by solubilizingCCI-779 with a parenterally acceptable cosolvent accompanied by thepresence of an antioxidant and/or chelating agent in the solution. Theparenteral formulation contains, in addition, a parenterally acceptablesurfactant.

In one aspect, this invention provides a CCI-779 cosolvent concentratewhich contains CCI-779, an alcoholic solvent, and an antioxidant.

In another aspect, the invention provides a parenteral formulationcontaining CCI-779, an alcoholic solvent, an antioxidant, a diluentsolvent, and a surfactant.

In yet another aspect, the invention provides a process for preparing aparenteral CCI-779 formulation by mixing CCI-779 with a parenterallyacceptable solvent and an antioxidant to provide a cosolventconcentrate; mixing a diluent solvent and a surfactant to produce adiluent; and mixing the cosolvent concentrate with the diluent toprovide the CCI-779 parenteral formulation.

Other aspects and advantage of the present invention will be readilyapparent from the foregoing detailed description of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Thus, the invention provides a CCI-779 cosolvent concentrate containingan parenterally acceptable solvent and an antioxidant as described aboveand a parenteral formulation containing CCI-779, composed of CCI-779, anparenterally acceptable cosolvent, an antioxidant, a diluent solvent,and a surfactant.

Any given formulation of this invention may contain multiple ingredientsof each class of component. For example, a parenterally acceptablesolvent can include a non-alcoholic solvent, an alcoholic solvent, ormixtures thereof. Examples of suitable non-alcoholic solvents include,e.g., dimethylacetamide, dimethylsulfoxide or acetonitrile, or mixturesthereof “An alcoholic solvent,” may contain one or more alcohols as thealcoholic solvent component of the formulation. Examples of solventsuseful in the formulations invention include, without limitation,ethanol, propylene glycol, polyethylene glycol 300, polyethylene glycol400, polyethylene glycol 600, polyethylene glycol 1000, or mixturesthereof. These cosolvents are particularly desirable because degradationvia oxidation and lactone cleavage occurs to a lower extent for thesecosolvents. Further, ethanol and propylene glycol can be combined toproduce a less flammable product, but larger amounts of ethanol in themixture generally result in better chemical stability. A concentrationof 30 to 100% v/v of ethanol in the mixture is preferred.

In the present invention, the stability of CCI-779 in parenterallyacceptable alcoholic cosolvents is enhanced by addition of anantioxidant to the formulation. Acceptable antioxidants include, but arenot limited to, citric acid, d,1-α-tocopherol, BHA, BHT,monothioglycerol, ascorbic acid, propyl gallate, and mixtures thereof.

Generally, the formulations of the invention will contain an antioxidantcomponent(s) in a concentration ranging from 0.001% to 1% w/v, or 0.01%to 0.5% w/v, of the cosolvent concentrate, although lower or higherconcentrations may be desired. Of the antioxidants, d,1-α-tocopherol isparticularly desirable and is used at a concentration of 0.01 to 0.1%w/v with a preferred concentration of 0.075% w/v of the cosolventconcentrate.

In certain embodiments, the antioxidant component of the formulation ofthe invention also exhibits chelating activity. Examples of suchchelating agents include, e.g., citric acid, acetic acid, and ascorbicacid (which may function as both a classic antioxidant and a chelatingagent in the present formulations. Other chelating agents include suchmaterials as are capable of binding metal ions in solution, such asethylene diamine tetra acetic acid (EDTA), its salts, or amino acidssuch as glycine are capable of enhancing the stability of CCI-779.

In some embodiments, components with chelating activity are included inthe formulations of the invention as the sole “antioxidant component”.Typically, such metal-binding components, when acting as chelatingagents are used in the lower end of the range of concentrations for theantioxidant component provided herein. In one example, citric acidenhanced the stability of CCI-779 when used at a concentration of lessthan 0.01% w/v. Higher concentrations are less stable solutions andthus, less desirable for products to be subject to long-term storage inliquid form. Additionally, such chelating agents may be used incombination with other antioxidants as part of the antioxidant componentof the invention. For example, an acceptable formulation may containboth citric acid and d,1-α-tocopherol. Optimal concentrations for theselected antioxidant(s) can be readily determined by one of skill in theart, based upon the information provided herein.

Advantageously, in the formulations of the invention, precipitation ofCCI-779 upon dilution with aqueous infusion solutions or blood isprevented through the use of a surfactant contained in the diluentsolution. The most important component of the diluent is a parenterallyacceptable surfactant. One particularly desirable surfactant ispolysorbate 20 or polysorbate 80. However, one of skill in the art mayreadily select other suitable surfactants from among salts of bile acids(taurocholate, glycocholate, cholate, deoxycholate, etc.) which areoptionally combined with lecithin. Alternatively, ethoxylated vegetableoils, such as a pegylated castor oil (e.g., such as PEG-35 castor oilwhich is sold, e.g., under the name Cremophor® EL polyethyleneglyceroltriricinoleat 35 (polyethoxy 35 castor oil), BASF), vitamin E tocopherolpropylene glycol succinate (Vitamin E TGPS), andpolyoxyethylene-polyoxypropylene block copolymers can be used in thediluent as a surfactant, as well as other members of the polysorbatefamily such as polysorbate 20 or 60 Other components of the diluent mayinclude water, ethanol, polyethylene glycol 300, polyethylene glycol400, polyethylene glycol 600, polyethylene glycol 1000, or blendscontaining one or more of these polyethylene glycols, propylene glycoland other parenterally acceptable cosolvents or agents to adjustsolution osmolarity such as sodium chloride, lactose, mannitol or otherparenterally acceptable sugars, polyols and electrolytes. It is expectedthat the surfactant will comprise 2 to 100% w/v of the diluent solution,5 to 80% w/v, 10 to 75% w/v, 15 to 60% w/v, and preferably, at least 5%w/v, or at least 10% w/v, of the diluent solution.

The parenteral formulation can be prepared as a single solution, orpreferably can be prepared as a cosolvent concentrate containingCCI-779, an alcoholic solvent, and an antioxidant, which is subsequentlycombined with a diluent that contains a diluent solvent and suitablesurfactant. Prior to use, the cosolvent concentrate is mixed with adiluent comprising a diluent solvent, and a surfactant. When CCI-779 isprepared as a cosolvent concentrate according to this invention, theconcentrate can contain concentrations of CCI-779 from 0.05 mg/mL, from2.5 mg/mL, from 5 mg/mL, from 10 mg/mL or from 25 mg/mL up toapproximately 50 mg/ml. The concentrate can be mixed with the diluent upto approximately 1 part concentrate to 1 part diluent, to giveparenteral formulations having concentrations of CCI-779 from 1 mg/mL,from 5 mg/mL, from 10 mg/mL, from 20 mg/mL, up to approximately 25mg/ml. For example the concentration of CCI-779 in the parenteralformulation may be from about 2.5 to 10 mg/mL. This invention alsocovers formulations having lesser concentrations of CCI-779 in thecosolvent concentrate, and formulations in which one part of theconcentrate is mixed with greater than 1 part of the diluent, e.g.,concentrate: diluent in a ratio of about 1:1.5, 1:2, 1:3, 1:4, 1:5, or1:9 v/v and so on, to CCI-779 parenteral formulations having a CCI-779concentration down to the lowest levels of detection.

Typically the antioxidant may comprise from about 0.0005 to 0.5% w/v ofthe formulation. The surfactant may for example comprise from about 0.5%to about 10% w/v of the formulation. The alcoholic solvent may forexample comprise from about 10% to about 90% w/v of the formulation.

The parenteral formulations of this invention can be used to produce adosage form that is suitable for administration by either directinjection or by addition to sterile infusion fluids for intravenousinfusion.

The following provide representative examples of the formulations ofthis invention. The preparation of CCI-779 is described in U.S. Pat. No.5,362,718, which is hereby incorporated by reference. A regioselectivepreparation of CCI-779 is described in U.S. Pat. No. 6,277,983, which ishereby incorporated by reference.

When the drug is given by direct injection, a diluent formulation thatis primarily aqueous is most suitable, although not required. See, e.g.,Example 3. When the drug is administered by addition to sterile infusionsolutions, the diluent formulation can be either primarily aqueous,e.g., water, glucose solution, saline, buffered saline, and the like, ornonaqueous. In the latter case a water miscible cosolvent replaces waterin the diluent. Example 4 is a formulation that is nonaqueous and isintended to be added to sterile infusion solutions, such as 0.9% sodiumchloride injection, 5% dextrose injection, lactated ringers injection,and other commonly used intravenous infusion solutions prior toadministration via intravenous infusion.

Cosolvent Concentrate

EXAMPLE 1

CCI-779 25 mg Citric acid, anhydrous 0.005% w/v Dehydrated ethanol, USPq.s. 1.0 ml

The above formulation was packaged in a glass ampoule with anitrogen/air headspace and had a shelf-life of 18-30 months when storedat 2-8° C.

EXAMPLE2

CCI-779 25 mg dehydrated ethanol, USP 0.395 g citric acid, anhydrous,USP 0.025 mg [0.0025% w/v] d,l-α-tocopherol, USP 0.75 mg [0.075% w/v]propylene glycol, USP q.s. 1.0 mL

The above formulation was packaged in a vial with a nitrogen/airheadspace. It has demonstrated good stability after 24 months storage at2-8° C. and room temperature. No significant degradation had beenobserved after 24 months at 5° C. Both formulations presented inExamples 1 and 2 can be sterilized by aseptic filtration.

Example 3 is a formula that contains a non-alcoholic cosolvent as theprimary vehicle:

EXAMPLE 3

CCI-779 25 mg Citric acid, anhydrous 0.025 mg D,L-α-tocopherol, USP 0.75mg N,N-dimethylacetamide q.s 1.0 mL

Exposure to short-term temperature stress indicated that the aboveformula was stable (greater than 97% potency was retained after exposureto stress temperature conditions (e.g. 70° C.) for at least 24 hours).

Diluents

EXAMPLE 4

Polysorbate 80, NF 5% w/v Polyethylene glycol 400 NF 5% w/v Water forinjection, USP q.s. 100%

This formulation can be packaged in vials, sealed and sterilized byautoclaving. The above formulation can be preferably combined in a ratioof 9:1 v/v with the cosolvent concentrate of Example 1 or 2 to produce asolution of CCI-779 at a concentration of 2.5 mg/ml. The resultingmixture can be injected directly or further diluted with 0.9% SodiumChloride Injection or 5% Dextrose Injection to provide a solution forintravenous infusion. Such mixtures are physically and chemically stablefor several hours at room temperature. The above diluent, when combinedwith the CCI-779 formulations in Examples 1 and 2, have been used todeliver doses of 0.5 to 500 mg CCI-779 via direct intravenous injectionor intravenous infusion.

Additional examples of diluent formulas which have a primarily aqueouscomposition are given below:

EXAMPLE 5

Cremophor ® EL (polyethoxy 35 castor oil)  10 w/v % Water for Injectionq.s. 100 w/v %

In this example, the diluent was combined with an equal volume of aCCI-779 concentrate (e.g. Example 2 above) to produce a largely aqueousvehicle that was physically stable for several hours at roomtemperature. This mixture could be suitable for direct intravenousinjection.

EXAMPLE 6

Vitamin E TPGS NF 10 w/v % Water for Injection, USP q.s 100 w/v %

The above formula was combined with an equal volume of CCI-779concentrate (e.g. Example 2 above) to produce a largely aqueous vehiclethat was physically stable for several hours at room temperature. Theresulting concentrate-diluent mixture could also be diluted with 0.9%sodium chloride injection without evidence of drug precipitation.Example 6 is a diluent suitable for direct intravenous injection ofCCI-779 (e.g. IV push) or intravenous infusion following dilution insterile infusion solutions.

EXAMPLE 7

Polysorbate 20 10% w/v Water for Injection, USP q.s. 100% w/v

The diluent in Example 7 was combined with an equal volume of CCI-779concentrate (e.g. Example 2) to produce a mixture that was physicallystable for several hours at room temperature. The concentrate-diluentmixture can be used for administration of CCI-779 via IV push.

EXAMPLE 8

Polysorbate 80, NF   40% w/v Dehydrated ethanol, USP 19.9% w/vPolyethylene glycol 400, NF q.s. 100%

The above formulation was sterilized by aseptic filtration. The aboveformula can be combined with the cosolvent concentrates of Example 1 or2 preferably in a volume ratio of 1.5:1 to produce a solution containing10 mg/ml CCI-779. This can be further diluted with 0.9% Sodium Chlorideinjection or 5% Dextrose Injection to provide a solution for intravenousinfusion. These mixtures are physically and chemically stable forseveral hours at room temperature. The above diluent, when combined withthe CCI-779 formulations in Examples 1 and 2, are useful for deliveringdoses of 2 to 500 mg via intravenous infusion.

EXAMPLE 9

Polysorbate 20 20% w/v Polyethylene glycol 400 q.s 100% w/v

The above formula was combined with an equal volume of CCI-779concentrate (e.g. Example 2) to produce a clear mixture. Theconcentrate-diluent mixture can be diluted with 0.9% sodium chlorideinjection to produce a mixture that was physically stable for severalhours at room temperature. Example 9 can be used to administer CCI-779via intravenous infusion.

The examples herein illustrate the formulations of the invention andtheir preparation, but are not limiting. It will be readily understoodthat other solvents, antioxidants, diluents and/or surfactants can beutilized in the present invention. In addition, numerous modificationsto the examples are encompassed by the scope of the following claims.All documents identified herein and priority applications, i.e., U.S.patent application Ser. No. 13/206,641, filed Aug. 10, 2011, U.S. patentapplication Ser. No. 10/626,943, filed Jul. 25, 2003, and U.S.Provisional Patent Application No. 60/399,526, filed Jul. 30, 2002, areincorporated by reference herein.

What is claimed is:
 1. A CCI-779 cosolvent concentrate comprising: (i)about 25 mg/mL of CCI-779; (ii) about 40% w/v of dehydrated ethanol;(iii) about 50% w/v of propylene glycol; (iv) about 0.075% w/v ofd,1-α-tocopherol; and (v) about 0.0025% w/v of citric acid.
 2. TheCCI-779 cosolvent concentrate according to claim 1, which is diluted ata ratio of 1:1.5 concentrate to diluent to form the parenteralformulation.
 3. A CCI-779 cosolvent concentrate comprising: (i) about 25mg/mL of CCI-779; (ii) 39% w/v of dehydrated ethanol; (iii) about 50%w/v of propylene glycol; (iv) about 0.075% w/v of d,1-α-tocopherol; and(v) about 0.0025% w/v of citric acid.
 4. The CCI-779 cosolventconcentrate according to claim 3, which is diluted at a ratio of 1:1.5concentrate to diluent to form the parenteral formulation.
 5. A CCI-779cosolvent concentrate comprising: (i) about 25 mg/mL of CCI-779; (ii)about 40% w/v of dehydrated ethanol; (iii) 51% w/v of propylene glycol;(iv) about 0.075% w/v of d,1-α-tocopherol; and (v) about 0.0025% w/v ofcitric acid.
 6. The CCI-779 cosolvent concentrate according to claim 5,which is diluted at a ratio of 1:1.5 concentrate to diluent to form theparenteral formulation.
 7. A CCI-779 cosolvent concentrate comprising:(i) about 25 mg/mL of CCI-779; (ii) about 39% w/v of dehydrated ethanol;(iii) 51% w/v of propylene glycol; (iv) about 0.075% w/v ofd,1-α-tocopherol; and (v) about 0.0025% w/v of citric acid.
 8. TheCCI-779 cosolvent concentrate according to claim 7, which is diluted ata ratio of 1:1.5 concentrate to diluent to form the parenteralformulation.